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Phosphatidylinositol-3,4,5-trisphosphate-dependent Rac exchange factor 1
Available structures
PDB Ortholog search: PDBe, RCSB
Symbols PREX1 ; P-REX1
External IDs OMIM606905 MGI3040696 HomoloGene10821 GeneCards: PREX1 Gene
RNA expression pattern
PBB GE PREX1 gnf1h08616 at tn.png
More reference expression data
Species Human Mouse
Entrez 57580 277360
Ensembl ENSG00000124126 ENSMUSG00000039621
UniProt Q8TCU6 Q69ZK0
RefSeq (mRNA) NM_020820 NM_177782
RefSeq (protein) NP_065871 NP_808450
Location (UCSC) Chr 20:
47.24 – 47.44 Mb
Chr 2:
166.57 – 166.71 Mb
PubMed search [1] [2]

Phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger 1 protein is a protein that in humans is encoded by the PREX1 gene.[1][2][3][4]


The protein encoded by this gene acts as a guanine nucleotide exchange factor for the RHO family of small GTP-binding proteins (RACs). It has been shown to bind to and activate RAC1 by exchanging bound GDP for free GTP. The encoded protein, which is found mainly in the cytoplasm, is activated by phosphatidylinositol-3,4,5-trisphosphate and the beta-gamma subunits of heterotrimeric G proteins.[4]

Clinical significance[edit]

The protein has been implicated in the spread of melanoma skin cancer.[5]


  1. ^ Welch HC, Coadwell WJ, Ellson CD, Ferguson GJ, Andrews SR, Erdjument-Bromage H, Tempst P, Hawkins PT, Stephens LR (Apr 2002). "P-Rex1, a PtdIns(3,4,5)P3- and Gbetagamma-regulated guanine-nucleotide exchange factor for Rac". Cell 108 (6): 809–21. doi:10.1016/S0092-8674(02)00663-3. PMID 11955434. 
  2. ^ Hill K, Krugmann S, Andrews SR, Coadwell WJ, Finan P, Welch HC, Hawkins PT, Stephens LR (Feb 2005). "Regulation of P-Rex1 by phosphatidylinositol (3,4,5)-trisphosphate and Gbetagamma subunits". J Biol Chem 280 (6): 4166–73. doi:10.1074/jbc.M411262200. PMID 15545267. 
  3. ^ Mayeenuddin LH, Garrison JC (Jan 2006). "Phosphorylation of P-Rex1 by the cyclic AMP-dependent protein kinase inhibits the phosphatidylinositiol (3,4,5)-trisphosphate and Gbetagamma-mediated regulation of its activity". J Biol Chem 281 (4): 1921–8. doi:10.1074/jbc.M506035200. PMID 16301320. 
  4. ^ a b "Entrez Gene: PREX1 phosphatidylinositol 3,4,5-trisphosphate-dependent RAC exchanger 1". 
  5. ^ Lindsay CR, Lawn S, Campbell AD, et al. (2011). "P-Rex1 is required for efficient melanoblast migration and melanoma metastasis". Nature Communications 2: 555. doi:10.1038/ncomms1560. Lay summaryCancer Research UK. 

Further reading[edit]